From Introduction:
Welcome to the world of "Ad Astra", a SF campaign setting. This document shall give players and game masters a quick overview about the setting.
The primer is presented in a system-free format to allow the GM to use any rules system he likes.
"Ad Astra" is set into the far future. Humanity has ventured to the stars. Aside from a few artifacts found in the lifeless deserts of Mars, there are no signs of intelligent life. Humanity is all alone in space. Or so it seems.
An ancient jumpgate found near Jupiter allowed us access to a far away region of space: the Omega Centauri star cluster. In the early years of the 22nd century millions of humans travelled to the stars, seeking a better life among the stars.
Scattered among these human colonies live the espers, humans with amazing psychic abilities that are the legacy of an alien species, called the Elohim.
Then suddenly the jumpgate was destroyed, the colonists where stranded in a far away sector of space. Hundreds of years later Earth is just a distant memory.